"I agree with Mr. Damon," Ned said. "It seems to work perfectly. And you have, I believe, established your required speed."

"Can't be too perfect," said the young inventor, smiling. "But I will tell Mr. Bartholomew when we get back that he can set his time for the big test whenever he pleases. I have already sent our patent attorney in Washington the final blueprints. Now, if nothing happens—"

"Bless my stickpin!" exclaimed Mr. Damon, "What can happen now that the locomotive is practically perfect?"

That question was answered in one way, and a most startling way, within the hour. Tom got right of way back over the mountain and pushed the electric locomotive up-grade at almost top speed. He drew no train on this occasion, and the speed made by the Hercules 0001 was really remarkable.

They topped the rise at Cliff City and got orders from the dispatcher to proceed on the time of Number Eighty-seven, which chanced to be late. With that release Tom might have made the entire distance of a hundred and ten miles to Hendrickton had it not been for the accident—the unexpected something that so often happens in the railroad business.

Tom was a careful driver; the chatter of Ned and Mr. Damon did not take the inventor's mind off his business for one instant. He was quite alert at his window, looking ahead, as Koku was at the open doorway of the cab.

Not a mile outside of Cliff City, and on this eastbound side of the right of way, was a long siding and a shipping point for timber. It was sometimes a busy point; but at this time of year there were no lumbermen about and no activities in the adjacent forest.

The Hercules 0001 came spinning along from the Cliff City yards, and Tom Swift gave scarcely a glance to the joint of the switch ahead. He had been over it so many times of late, and knew that it was always locked. The railroad did not even keep a man here at this season.

Suddenly Koku emitted a wild yell. He startled everybody else in the cab, as he flung his huge body more than half out of the doorway and prepared to jump—or so it seemed.

Ned shrieked a warning to the big fellow. Mr. Damon began to bless everything in sight. But it was Tom, quite as excited as his friends, who understood what Koku shouted: